This invention relates generally to the separation of particulate materials from liquidic suspension. More specifically, the invention relates to a novel and unique filter-separator pour-out cap for a container that has particulate materials in liquidic suspension. The cap enables the liquid to be poured from the container free of particulate materials above a given size while such particulates remain trapped inside the capped container.
Industrial processes in which particulate materials are held in liquidic suspension often require separation of the particulate materials from the liquid. Devices, often called filters, separators, or filter-separators, are used for this purpose. Generally they are of two types.
The first type is a screen that comprises woven wires, either metal or plastic. It possesses a unique characteristic in that while it is woven to comprise square openings, those openings are really three dimensional in nature because of the weaving of the wires. If the particulate material that is being separated contains some particles whose dimensions are essentially equal to those of the square openings in the filter screen, then such particles often become entrapped in the openings. Because of the three dimensional nature of the woven filter, it is rather difficult, and often impossible, to dislodge these entrapped particles, even by backwashing. If there are many particles of this particular size that become entrapped in many of the square openings of the filter, the filter becomes "blinded", ceasing to function effectively in the areas of blinding, with attendant attenuation of flow.
The second type of filter is typically made of woven paper or selectively etched material. In either case, this type of filter is also three dimensional in character and subject to blinding. Because both filter types are relatively inexpensive. They are typically replaced by fresh ones when they become excessively blinded.
In certain processes an unacceptable degree of filter blinding may occur at times or under circumstances that are not especially conducive to filter replacement. Moreover, the mere act of replacing a filter involves the expenditure of a certain amount of time and effort, even if the time and circumstances are not inconvenient for filter replacement, and even though the cost of filters of the aforedescribed types may be relatively inexpensive. Furthermore, for additional reasons, it is usually necessary to periodically replace filters with brand new ones, a further cost for the overall process.
Certain filtering, or separating, operations are conducted on particulate-containing liquidic media that are in bottles. Placement of a filter screen over the bottle opening and pouring the media through the filter is one typical type of filtering procedure. Generally, the filter area is comparatively small, and clogging or blinding may seriously impair the dispensing of the liquid before the entire liquid contents of the container have been poured out.
The present invention relates to a new and improved filtering, or separating, device that filters particulate material from particulate-containing liquidic suspension in a new and unique way that avoids the blinding tendency of three dimensional type filter screens. More specifically, the invention involves a new "two dimensional" principle of filtering which avoids the particulate entrapping effect that characterizes the three dimensional types of filters described above.
The invention has special advantages in a pour-out cap for a container because one it does not have this blinding tendency that characterizes three dimensional types of filters and two, even if separated particulate material tends to begin obstructing flow through the cap, such clogging can be relieved by turning the container upright and/or by moderately shaking or jarring the container.
A filter-separator device embodying principles of the present invention can be conveniently manufactured by known fabrication techniques. A preferred method of making the device is through the use of plastic materials which can be molded to desired shapes by means of suitably constructed molds. It is possible, however, to fabricate the device of the present invention by other techniques.
The foregoing features, advantages, and benefits of the invention, along with additional ones, will be seen in the ensuing description and claims which should be considered in conjunction with the accompanying drawings. The drawings disclose a preferred embodiment of the invention according to the best mode contemplated at the present time in carrying out the invention.